20120927

Astronomy quiz question: HESS interferometry

Consider two of the High Energy Stereoscopic System telescopes, located near Windhoek, Namibia. These two reflector telescopes have different diameters, and different focal lengths. These and other HESS telescopes were constructed to be spread out from each other to improve:
(A) light-gathering power.
(B) resolving power.
(C) magnifying power.
(D) (Two of the above choices.)
(E) (All of the above choices.)
(F) (None of the above choices.)